Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to communications on high-speed trains (HSTs).
Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, and orthogonal frequency-division multiple access (OFDMA) systems, and single-carrier frequency division multiple access (SC-FDMA) systems.
These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. For example, a fifth generation (5G) wireless communications technology (which can be referred to as 5G new radio (5G NR)) is envisaged to expand and support diverse usage scenarios and applications with respect to current mobile network generations. In an aspect, 5G communications technology can include: enhanced mobile broadband addressing human-centric use cases for access to multimedia content, services and data; ultra-reliable-low latency communications (URLLC) with certain specifications for latency and reliability; and massive machine type communications, which can allow a very large number of connected devices and transmission of a relatively low volume of non-delay-sensitive information. As the demand for mobile broadband access continues to increase, however, further improvements in 5G communications technology and beyond may be desired.
HST systems can be equipped to support wireless communications for user equipment (UE) aboard the HST. For example, a HST system can include a plurality of remote radio heads (RRHs) for one or more base stations to facilitate UE communications with the base stations using the RRHs. The RRHs can be located near the HST track, for example, and can utilize a single frequency network (SFN) to communicate with one or more UEs to minimize a number of handovers of the UE among the RRHs. In an example, 5G NR may (or may be required to) support up to 500 kilometers per hour (km/h) HSTs.